Conventionally, communication apparatuses which selectively perform facsimile communication via the Internet and facsimile communication without the Internet are known. For example, a facsimile apparatus which selectively performs facsimile communication via the Internet in conformance with the ITU-T Recommendation T.38 and normal facsimile communication via a PSTN (Public Switched Telephone Network) are known.
In prior facsimile apparatus, in any case of facsimile communication via the Internet and facsimile communication without the Internet, communication parameters such as transmission speed and delay time are fixed.
For example, in the facsimile communication via the Internet in conformity with the ITU-T Recommendation T.38 and in the normal facsimile communication via the PSTN, facsimile communication is performed with the communication parameters fixed to values based on the ITU-T Recommendation T.30.
However, in the conventional art, upon execution of facsimile communication via the Internet, there is an occurrence of a delay caused by the Internet. In addition, PSTN communication between a facsimile apparatus at the transmitting side and an emitting gateway, and PSTN communication between a receiving gateway and a facsimile apparatus at the receiving side result in doubling the PSTN communication via modems. This results in communication errors being increased in comparison with the normal facsimile communication via a PSTN.